Variable speed transmission



Oct. 3, 1939- H. E. AvoNDE ET AL VARIABLE SPEED TRANSMISSION Filed Aug. 27, 1938 2 Sheets-Sheet l www Oct. 3, 1939. H. E. AvoNDE x-:T AL 2,175,012

VARIABLE SPEED TRANSMISS ION Filed Aug.' 27, 1938 2 sheets-sheet 2 ATTar/ve/ Patented Oct. 3, 1939 e UNITED STATES PATENT OFFICE VARIABLE SPEED TRANSMISSION Henri Ernest Avonde and Sydney John Albin, Hamilton, Ontario, Canada Application August 27,. 1938,A Serial No. 227,080

' 3 claims. (C1. vla-336.51)

This invention relates to variable speed transparts being secured together by locking screws missions and more particularly to a transmission 2U.. A flange` 2| is formed on the outer peripheral wherein means are pro-vided for automatically edgeof each part I6 and I1 to provide a groove in connecting'driving and driven shafts at different which the external member I5 seats. The inner speed ratios. face of each part I6 and I1 is recessed to form 5` An object of the invention is to providea simplel housings 22 each adapted to receive a spring 23 arrangement, which will be positive in operation, and plunger 24. The plungers 24 extend through for effecting automatically the variable speed corresponding openings 25 in the shaft I and connections between the driving and driven normally project through such openings into a 10,. shaftsin accordance with the speed of rotation bore 26 in the shaft under the influence of 10 of the driving. shaft. springs 23. The inner ends of the plungers are Another object is. to provide an. automatic provided with rollers 21. Notches or recesses 28 transmission device with which may be convenare-formed in the external member I5, each notch iently incorporated a means forsynchronously being'adapted to receive the outer end of a coractuating a clutch in association therewith. responding plunger. The edges of the notches 15 Other objects of the invention will be apparent and of the heads of the plungers are bevelled from the descriptio-n which follo-wswith reference as shown to ensure ,a ready engagement and to the accompanying drawings, in whichdisengagement of the plunger heads and the FigureV 1. is a diagrammatic plan of an arrangenotches. 20. ment according to the invention; and Means for forcing the plungers outwardly to 20 Figures 2 to 10 are'enlarged sectional views of engage the'notches 28 and thus lock the external various details of the arrangement shown in and internal gear members together comprises a Figure 1. control rod 29 slidingly mounted within the bore The invention as illustrated is adapted to be 26V and having a cam surface 30 thereon adapted 2,5. applied to'aconventional motor car havingadrivto engage the inner ends of the plungers and 25;

ing shaft I, a driven shaft` 2, a. clutch 3 inV the force the same outwardly.

driving shaft, a y Wheel 4 on the driving shaft As illustrated clearly in Figure 6, the control and asteering wheel. 5.` rod 23 extends through the end of the driving The transmission is adapted to provide the shaft I-, a keyway 3| being formed in the rod and 30: usualthree speeds forward and one speed reverse. a key bushing 32 being provided in the bore 30` The three speeds forward are.- obtained through adjacent the end of the shaft.

three gears 6, 1l and 8 onl the driving shaft and The outwardly extending end o-f the control rod three gears 9, Ill and II onv the driven shaft in 29 is swivelly secured in a housing 33. The swivel constant mesh therewith. These gears are of mounting comprises a bearing 34 screwed onto 35 varying diameter corresponding with the varying the end of the rod, which bearing freely revolves 35:

speeds required. Reverse speed is'r obtained on ball bearings 35. The housing 33 is slidingly through av gear I2 onl the driving shaft,. a gear mounted on glide rods 36, ball bearings 31 being i3' on the driven shaft and an idler gear I4 inprovided in the housing for ease of movement. constant mesh with each gear I2 and I3-. All of Movement of the housing with control rod j they gears are preferably of the double helical along the glide rods 36 is effected by means of 40 type to ensure greater efficiency and more silent an arm- 38 pivotally mounted at 39 and having operation. slots 40 in either end thereof. A pin 4I carried Gears 6:, 1:, 8 and I2. are of special construction by housing 33 extends through one of the slots whereby they may be locked to the driving shaft 40 and a pin 42 carriedl by a sliding platform or i5y for rotary movement therewith or may be discarriage 43 extends through the other slot. The 45 connected inpart therefrom to allow the gear platform 43 is mounted at one end on a bracket face tov remain stationary irrespective of revolu- 44 slidingly carried by glide rods 45. Ball beartion' of the shaft.Y As shown in Figures 6, '7 and 8, ings 46 may be provided in the bracket for ease each of theseY gears comprises an external annuof movement as shown in Figure 4. The otherlar memberl .I5I and an internal memberv composed end of platform 43 is mounted on a housing 41. 50 of two parts I6 and I-1- mounted onthe driving The-housing 41 is composed of two parts 48 and shaft l. The parts I6 and I1 are in the form 49, whereby the same may be mounted on a shaft of annu-lar plates which fit into locking engage- 50 by means of bolts 5I which extend through men-t with each other. Part I6 has key recesses each` part and the platform 43. The housing 41 I8 therein toreceive keys I9 on part I1, the slides on the shaft 50 with the platform 43, ball 55 ing 59 mounted on ball bearings S0 within thel housing 41 and screwed onto a portion 5l of the bracket 58 which extends into the housing. A spring S4 mounted on shaft 5U and extending between brackets 56 and 58 tends to urge the weights 54 into their normal at rest position.

Rotary movement of the shaft 50 is imparted thereto by means of a relatively small gear 62 thereon which meshes with the flywheel gear 4.

Sliding movement may also be imparted to the platform 43 by manual means comprising a rack 63 on the platform and a suitably mounted gear segment 64 meshing therewith. A connecting rod B5 is provided between an arm 66 of the segment 64 and a crank arm 61 on a shaft 68. A bevel .gear 69 on shaft 68 meshes with a bevel gear lil on a shaft 1I which may extend within the steering column as shown in Figure 10, upwardly to the steering wheel 5. A crank arm 12 is formed on the end of shaft 1I and a control handle 13 is secured thereto. As shown, the handle 13, which is pivoted at 14, has a projection 15 thereon adapted to fit into one of two 'corresponding recesses 16 in a steering wheel member 11. A spring 18 urges the handle upwardly whereby, when the projection 15 is in registry with one of the recesses 16, it will automatically engage the same to lock the handle in a certain position.

The control handle, which is adapted to place the mechanism in neutral, reverse or forward driving positions, is arranged to be locked, in the manner just described, in neutral or reverse driving positions but not in forward driving position. The three positions may be designated on the steering wheel as illustrated in Figure 1.

Means for synchronously actuating the clutch 3 is provided and comprises a cam rack 19 on the platform 43 and a lever 8D pivoted at Si having one end provided with a suitable cam engaging surface, such as a wheel 32, and the other end engaging the member 83 of the clutch and adapted to apply pressure thereon to release the clutch.

The specific operating details of the invention will now be described.

With the control handle 13 locked in neutral position, the various parts of the apparatus are so arranged that the cam-engaging wheel 82 of the lever is positioned in one of the depressions of the cam rack and the clutch engaged, and the cam surface 39 of the control rod 29 is positioned between gears 6 and l2 on the driving shaft and all gears of the transmission are motionless.

With the motor idling and a forward movement of the vehicle desired, the handle 13 is depressed by the driver to disengage the lock and moved to the right. In this connection, it should be noted that the placement of the neutral setting is located slightly in advance of the normal at rest position of the centrifugal device, such point being the center of balance between the centrifugal and spring pressures. Thus, ease of movement of the control handle either to forward or reverse position from neutral is assured. With release of the handle from its locked position, the

control rod 29 is now freely responsive to actuation by the centrifugal device. It will be noted that the centrifugal device is directly responsive to the speed of the motor since the shaft 50 is rotated by the fly wheel 4. Moreover, the shaft 50 is caused to rotate at a speed ratio considerably faster than that of the motor thus permitting the use of minimum size of iron weights in relation to the centrifugal force generated.

With acceleration of the motor, therefore, the weights 54 move outwardly to pull platform 43 to the left and move the control rod 29 to the right. This movement of the control rod places its cam surface 30 into engagement with plungers 24 of gear E to connect the same with the driving shaft for rotary movement therewith. The clutch actuating mechanism is so synchronized with the latter operation that during the connection of the gear 6 with the driving shaft, the clutch is released through actuation of the lever 80 by engagement of a projecting surface of the cam rack 19 with the wheel 82. As the connection is completed, the clutch is allowed to engage and motion is transmitted from the driving shaft through gears 5 and 9 to the driven shaft. As the acceleration of the motor and vehicle increases, the pull of the centrifugal device increases and the gear connections are automatically shifted from gears 6 and 9 to gears 1 and I0 and then to gears 3 and Il, which constitute the normal drivingr or high gear connection. The spacing between each gear constitutes the idling period of the gear shift synchronizing with the clutch release. The cam surface of the cam rack 10 permits a gradual engagement and disengagement of the clutch and the timing thereof is so related to the gear changing mechanism that there is no grab or jerkiness in the movement.

When .acceleration is decreased, a reverse gear shifting action automatically takes place, this action constituting a braking force of great value in the operation of the vehicle. Thus, when it is desired to stop the vehicle, the accelerator is released and the brakes applied. The gears automatically shift from high to second to low speeds and finally to neutral, in which the mechanism is locked automatically. Moreover, the proper gear connection will be selected to meet all driving conditions. When ascending a steep grade, for instance, should the pull on the motor reach a certain value, an automatic shift to second or first speed will be made. Should it be necessary to slow up the vehicle, the proper gear connection will be selected to maintain the vehicle at any desired low speed. Acceleration of the vehicle an-d shifting from low to second to high speeds is accomplished at .any rapidity the driver may desire depending upon the acceleration imparted to the motor. Should the motor become stalled for any reason, the transmission reverts` itself to low gear and thence to neutral position immediately.

When it is desired to proceed in reverse gear, the handle 13 is moved to the reverse position where it is locked in position. This movement shifts control rod 29 to place its cam surface 30 in engagement with the plungers 24 of gear l2 whereupon the latter rotates with driving shaft I and imparts reverse rotary movement to driven shaft 2. The clutch 3 is synchronously actuated in relation to the latter operation in the manner previously described.

The spring 84 is preferably provided with an overplus tension and the weights 54 are likewise preferably provided with an overplus capacity.

This overplus reserve in the centrifugal device assures a more efficient operation of the mechanism. Thus, the equilibrium of the centrifugal device is such that the spring tension provides a thrust which is more than sufficient to accomplish its work of effecting the shift from high speed to neutral and the centrifugal balance of power provides more than the required pull to compress the spring and effect the shift from' low to high speeds.

We claim:

1. In an automatic transmission having a driving shaft and a driven shaft, a series of gears on the driving shaft normally in disconnected driving relation therewith, a second series of gears on the driven shaft in constant mesh with said rst series of gears, a cam member arranged to connect successively each of the gears of the fn'st series with the driving shaft to be driven thereby, and automatic means for actuating said cam member comprising a control shaft geared to the driving shaft for rotation at a higher rate of speed than the driving shaft, centrifugal means responsive to the speed of rtation of said control shaft, a reciprocally mounted platform movable by said centrifugal means, and a pivotally mounted arm having one end connected to said platform and the other end connected to said cam member.

2. An automatic transmission having a driving shaft, a driven shaft, a normally engaged clutch in said driving shaft, a gear fixed to the driving shaft at one side of said clutch, a series of gears on the drivin-g shaft at the other side of said clutch and normally in disconnected driving relation therewith, a series of gears on the driven shaft in constant mesh with the rst series of gears, a reciprocally mounted cam member arranged to connect successively each of the gears of the first series with the driving shaft to be driven thereby, and automatic means for actuating said cam member comprising a control shaft having a relatively small gear meshing with said first-mentioned gear whereby said control shaft may be rotated by the driving shaft at a higher rate of speed than that of the driving shaft, centrifugal means responsive to the speed of rotation of said control shaft, a reciprocally mounted platform movable by said centrifugal means, and a pivotally mounted arm having one end connected to said platform and the other end connected to said cam member.

3. An automatic transmission having a driving shaft, a driven shaft, a normally engaged clutch in said driving shaft, a gear fixed to the driving shaft at one side of the clutch, a series of gears on the driving shaft at the other side of the clutch and normally in disconnected driving relation therewith, a series of gears fixed to the driven shaft in constant mesh With the rst series of gears, a reciprocally mounted cam member arranged to connect successively each of the gears of the first series with the driving shaft to be driven thereby, a control shaft geared to said first-mentioned gear for rotation by the driving shaft at a higher rate of speed than that of the driving shaft, centrifugal means responsive to the speed of rotation of the control shaft, a reciprocally mounted platform' movable by said centrifugal means, a pivotally mounted arm for actuating said cam member having one end connected to said platform and the other end connected to said cam member, a cam surface on said platform, and a pivotally mounted arm for actuating said clutch having one end engaging said cam surface and the other end engaging said clutch.

HENRI ERNEST AVONDE. SYDNEY JOHN ALBIN. 

